The Upper Tisa Valley. Preparatory proposal for Ramsay

also to tha drier climate that was prevalent in the northeastern part of the Great
Hungarian Plain during the Late Glacial (Willis et al. 1995).
The late-glacial/postglacial transition occurred between approximately 10.000-
9200 years BP. Computer simulated climatic modelling (Kutzbach-Guetter, 1986,
Kutzbach et al. 1993) suggest that during this period the climate became progressively
warmer. This climatic change at the late-glacial/postglacial transition resulted in a
gradual transformation of Nyíres-tó at Csaroda. The Picea coniferous woods declined
and mixed Quercus/Ulmus/Corylus woodland became established. The early
postglacial woodland, although dominated by Quercus, was still characterised by the
presence of Picea. It appears that it took more than 1000 years for this tree species to
disappear from the forests, only when Quercus woodland expanded and become
predominant. This woodland was composed of Quercus, Corylus, Ulmus, Tilia,
Fraxinus, Alnus and accounted for over 90 % of the total pollen.
Microcharcoal records (Fig. 9.) from the late-glacial/postglacial transition
suggest that burnings decreased only gradually and parallel with the decrease of Picea
pollen values in the Nyíres-tó. When Picea declined and Quercus/Corylus/Ulmus/Tilia
hardwood forest established, a cessation of burning occurred, since broad-leaved trees
are known to be less combustible than the needle-leaved Picea (Johnson, 1992),
thereby the forest became less flammable.
The change at the late-glacial/postglacial transition from coniferous to
deciduous woodland is unusual in central and southern Europe, because most regions
experienced a change from steppe or forest steppe to deciduous forest (Bottema, 1974,
Huntley-Birks, 1982, Willis, 1992, Járainé-Komlódi, 1966). Nevertheless, this type of
forest-to-forest change developed in yet another region of the northeastern part of the
Carpathian basin (Willis et al. 1995, 1997).
Parallel with vegetation changes, there was an increase in the level of calcium
and organic material entering the basin, from about 9000 years BP. The acid nature of
the bedrock and low levels of calcium input prior to this increase suggest that, again,
processes other than physical weathering are responsible for this increase.
Measurements of the chemical elements in leaf litter suggest that deciduous litter has
higher levels of calcium than coniferous litter (Willis et al. 1997). Thus, this increase
in calcium, which is associated with the transition from mixed leaved taiga forest to
deciduous forest, represents throughflow from deciduous litter depositions and the
leaching of Ca from the brown earth soils (Willis et al. 1997).
According to archaeological data (Fig. 9), Mesolithic human communities
existed in this region (Matskevoi, 1991, Chapman, 1994, Kertész et al. 1994) where
they used the habitat for hunting-fishing-gathering, yet human role in nature was
already far from passive (Roberts, 1989). Palaeo-ecological data suggest that these
human populations lived in the closed forest environment in this region. This
conception is very different from the view of other authors (Járainé-Komlódi, 1987: p.
38, 41, Kertész, 1996: p. 18). It seems that some archaeologists and botanists did not
think about the effects of mosaic pattern environments which developed equally at
macro-, regional, and micro-levels in the Carpathian basin (Sümegi, 1996, Sümegi et
al. 1998).
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